1. Field of the Invention
This invention relates in general to equipment for drilling and producing subsea wells, and in particular to a seal assembly located at the top of a riser string extending between the subsea well and a floating drilling or production platform.
2. Description of the Prior Art
In U.S. Pat. No. 4,403,658, Sept. 13, 1983, Watkins, a single stab union is shown for an offshore drilling or production platform. In the patent, at the top of the riser run or string, a termination head is adapted to be received within a female termination housing. The termination housing has a number of radial ports that register with passages located in the termination head. These ports contain high pressure fluid for transmission between the vessel and the subsea well. If it is necessary to disconnect the lower end of the riser from the subsea well temporarily, the termination head can be pulled upward from the termination housing. The lines or hoses connected to the termination housing can remain in place, connected to the housing.
Seals are required to seal the junction of the termination housing radial ports with the termination head radial passages. In the patent, static elastomeric seals are shown encircling each outlet of the termination head ports.